2006.
2005.
2005.
2006.
In this year I have finalized the task concerning the comparison of multiresolution spatial data sets, and I decide to discard the temporal information. In particular I define a model for such sets, a model for both topological and cardinal relations. From the point of view of the multiresolution sets comparison I have defined a topological and cardinal distance function between multiresolution sets and also a similarity function between such sets.
My work on the task concerning the query process has been mainly focused on the query language, in fact I haved defined weak spatial (topological and cardinal) predicates based on the concepts of similarity and consistency between spatial relations. Moreover, I have used such predicates to define the semantics of a weak algebra. I decided to discard the local query processing, in order to address the new interesting issue of the quality of spatial data, thus I consider only the global query processing. Now I am studying the impact of the weak algebra in the global query processing.
The task on the data analysis has not been investigated yet, and we plan to address it only after the finalization of the other tasks.
2005.
In this year, I have improved my knowledge concerning spatial data and their related, such as the spatial relationships (topological, metrical, directional), the definition of multiresolution spatial datasets and the concepts of consistency and similarity between such datasets. I started to investigate data integration architecture, in particular the mediator system; in order to exploit spatial relation and multiresolution to improve query processing of such system.
During 2004-2005, I partecipated to the SPADA@WEB project. In this context, I contributed to define a model for multiresolution spatial vector maps, a set of topological relations and the concepts of topological consistency and similarity. I contributed, also, to define a computational method to evaluate both consistency and similarity. In order to test the effectiveness of the defined approaches, we performed some preliminarly experiments using both real and synthetic geographic datasets.
Concerning query processing my contribution is twofold. The first is a preliminary approach for progressive refinement of query results for multiresolution geographic databases in distribuited architectures. The second is a preliminary approach to query rewriting that introduces some mechanisms of query relaxation, in order to approximate the results of topological queries. PhD thesis proposal [pdf]
2006.
In this year I have finalized the task concerning the comparison of multiresolution spatial data sets, and I decide to discard the temporal information. In particular I define a model for such sets, a model for both topological and cardinal relations. From the point of view of the comparison I have defined a topological distance function between multiresolution sets, a cardinal distance function between multiresolution sets and also a similarity function between two multiresolution sets.
My work on the task concerning the query process has been focused on the query language, I haved defined weak spatial (topological and cardinal) predicates based on the concepts of similarity and consistency between spatial relations. I have used such predicates to define the semantic of a weak algebra. In the query processing I decided to discard the local query processing, in order to and to focus on the global query processing, now I am studying the impact of the weak algebra in the global query processing.
The task on the data analysis is totaly inexplored since now.
Considering the implementative side I have developed a prototype of the similarity distance between spatial relations and I have extended the query language, GQuery, and the API Java, JTS, in order to cope with weak spatial predicates. For more details see the progress report [pdf]